Resources

Magic: The Gathering Comprehensive Rules Changes

Core Set - Ninth Edition to Ravnica: City of Guilds (Single Change View)

General changes

Old rule (Core Set - Ninth Edition) New rule (Ravnica: City of Guilds)

408.1d.

A player may play a spell or activated ability only when he or she has priority. Spells other than instants can be played only during a player's main phase, when that player has priority and the stack is empty.

408.1d.

A player may play an instant spell or an activated ability any time he or she has priority. Spells other than instants may be played during a player's main phase, when that player has priority and the stack is empty.